BI256 Lecture Notes - Lecture 18: Malacostraca, Arthropod Leg, Remipedia
Document Summary
Lecture 18 arthropoda crustaceans part 1 - chapter 20 feb 15th. Mainly marine, but many fresh water and a few terrestrial spp. Most abundant animals in the world - members of the copepod genus calanus. Insects and crustacean compose over 80% of all named animal species. In most, one or more thoracic segments are fused with the head as a cephalothorax. Cuticle composed of chitin, protein and calcareous material. Head with pair of mandibles and 2 pairs of maxillae and 2 pairs of antennae. One pair of appendages on each of the addition segments although some segments may lack appendages, all appendages, except first antennae, are ancestrally biramous (dividing to form two branches) Anterior end is non segmented rostrum (beak like projection of head) Telson, with the last abdominal segment and uropods, forms a tail. Ancestral body plan (malacostraca (largest of the six classes of crustaceans): head has 5 fused segments, thorax has 8 segments, abdomen has 6 segments.
